1 Steam Cars : Phorum
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opposed piston engine
Posted by: Peter Heid (IP Logged)
Date: August 27, 2002 08:16PM
<HTML>A direct relative of the free piston engine is the opposed piston design and it has popped up for me again, in issue number 12, Jan/Feb 1991 of Old Glory magazine I happened across a Commer truck from 1960 with a Rootes opposed piston 3 cylinder 6 piston engine. It displaces 3.25 litres and produces 105 bhp at 2400 rpm and 270 foot pounds of torque at 1200 rpm using the 2 stroke cycle uniflow diesel principal. This is a very compact engine and makes great power for it's size. I have often wondered if any opposed piston engine, free or linked, has been tried in a steam version. You can't argue with compression ratios from 10:1 to 50:1, low parts count and uniflow design.
Peter Heid</HTML>
Peter Heid</HTML>
Re: opposed piston engine
Posted by: tom ward (IP Logged)
Date: August 27, 2002 09:08PM
<HTML>Opposed piston diesels were created during WW1 by Junkers. I've long thought a pair of regular 2 strokes could without their heads could be joined top to top with a chain drive between th cranks. For steam use you would double the exhaust port area. But could the cranks handle the tremendous torque loads?</HTML>
Re: opposed piston engine
Posted by: Terry Williams (IP Logged)
Date: August 27, 2002 10:21PM
<HTML>Lear tried it on the deltic engine.</HTML>
Re: opposed piston engine
Posted by: William L. Petitjean, P.E. (IP Logged)
Date: August 28, 2002 03:05AM
<HTML>Hmmm ..... an intriguing concept. Also, you will get a twice as much increase in cylinder volume per unit of stroke with a corresponding large expansion ratio. This means it is easier to run at excrutiatingly short cutoffs without wiredrawing yourself to death. Much better exhaust port area in two cylinder exhaust belts too. This means lower exhaust losses. Now if we just bathed the whole middle cylinder area in ring burners and used one of Petitjean's super ultrasonic injectors we could easily replicate the high MEP developed in the diesel version.
Unfortunately, what you gain in cylinder simplicity you lose in the complicated gear train that ties together the two crankshafts.
Bill Petitjean</HTML>
Unfortunately, what you gain in cylinder simplicity you lose in the complicated gear train that ties together the two crankshafts.
Bill Petitjean</HTML>
Re: opposed piston engine
Posted by: Peter Brow (IP Logged)
Date: August 28, 2002 05:06AM
<HTML>I wonder if anyone has ever considered rods and cranks, instead of gears, to link the two crankshafts in an opposed-piston engine? Probably not good for high rpms, but for a lower-rpm steam engine?
Peter</HTML>
Peter</HTML>
Re: opposed piston engine
Posted by: Brian Drake (IP Logged)
Date: August 28, 2002 06:41AM
<HTML>I've got a Popular Mechanics from the 1950's which features an opposed piston engine design that was based on ones used by the Germans in some of their U-Boats near the end of the war. These didn't have a crank or gear set up at all, but instead compressed large volumes of air that then powered a turbine. Theoretically, the design yielded the same fuel economy as ICE engines being produced today. There's been some research on it in modern times, but not a lot. I'll see if I can't find the site tomorrow from one company that's working on it.</HTML>
Re: opposed piston engine
Posted by: Mark Stacey (IP Logged)
Date: August 28, 2002 07:27AM
<HTML>Check out the book Some Unusual Engines by LJK Setright. It covers several opposed piston engines including the Rootes truck engine with its single crank, connecting rods, rocker arms, piston connecting rods and piston system, Junkers, Deltic, Gobron-Brille etc
Definitely worth a look or buying. Probably out of print but a troll through abe books should find a copy.
Cheers
Mark Stacey</HTML>
Definitely worth a look or buying. Probably out of print but a troll through abe books should find a copy.
Cheers
Mark Stacey</HTML>
Re: opposed piston engine
Posted by: Jim Crank (IP Logged)
Date: August 28, 2002 01:47PM
<HTML>Gentlemen,
An opposed piston unaflow engine would be a superb combination, if you wish to solve the water in the oil problem that plagues all single acting engines. This can be solved, however.
Fiat made a 1.5 liter six cylinder supercharged racing engine back in the 1920's, Type 451, I think, that gave more power than ever before in an engine of that size. Something like 165 HP at 8,000, until the plugs melted and the exhaust piston crown followed suit.
The basic idea goes back into the 19th century and it certainly worked well.
The Junkers Diesel aircraft engine, the Fairbanks-Morse submarine and railroad engine, to name only two that were in large scale production.
Lear's Deltic was based on the Napier marine engine; but failed because of the rotary inlet valve in the middle of the assembly and no oil water separator.
Consider this: perfect balance because of equal masses in opposite rotation. the engine can be laid flat under the car with the power taken off the cross connecting shaft. Probably the best design for minimal thermal losses. Thermal barrier coatings on the piston heads. Probably a slip joint in the connecting shaft to take care of block expansion and not mess up the gear clearances. Very high expansion ratio as Bill says.
Think of using the two crankshafts and connecting rods from the Detroit Diesel 51 series engine, they were made in opposite rotation, so the throws are mirror images of each other, as the basis of a steam engine. Made in three and four cylinder versions.
Study the design of the Fairbanks-Morse engine for how to make the cross shaft and it's gearing, they had it down pat.
One of my professors in college once stated: "If you want frantic output from a supercharged two stroke, the opposed piston it the only way to go."
This also applies to a steam engine.
Jim
Very much worthy of our consideration, if you stick with a piston engine.
Jim</HTML>
An opposed piston unaflow engine would be a superb combination, if you wish to solve the water in the oil problem that plagues all single acting engines. This can be solved, however.
Fiat made a 1.5 liter six cylinder supercharged racing engine back in the 1920's, Type 451, I think, that gave more power than ever before in an engine of that size. Something like 165 HP at 8,000, until the plugs melted and the exhaust piston crown followed suit.
The basic idea goes back into the 19th century and it certainly worked well.
The Junkers Diesel aircraft engine, the Fairbanks-Morse submarine and railroad engine, to name only two that were in large scale production.
Lear's Deltic was based on the Napier marine engine; but failed because of the rotary inlet valve in the middle of the assembly and no oil water separator.
Consider this: perfect balance because of equal masses in opposite rotation. the engine can be laid flat under the car with the power taken off the cross connecting shaft. Probably the best design for minimal thermal losses. Thermal barrier coatings on the piston heads. Probably a slip joint in the connecting shaft to take care of block expansion and not mess up the gear clearances. Very high expansion ratio as Bill says.
Think of using the two crankshafts and connecting rods from the Detroit Diesel 51 series engine, they were made in opposite rotation, so the throws are mirror images of each other, as the basis of a steam engine. Made in three and four cylinder versions.
Study the design of the Fairbanks-Morse engine for how to make the cross shaft and it's gearing, they had it down pat.
One of my professors in college once stated: "If you want frantic output from a supercharged two stroke, the opposed piston it the only way to go."
This also applies to a steam engine.
Jim
Very much worthy of our consideration, if you stick with a piston engine.
Jim</HTML>
Re: opposed piston engine
Posted by: Terry Williams (IP Logged)
Date: August 28, 2002 02:09PM
<HTML>Jim, Fairbanks certainly had the opposed piston diesel down pat. I spent several years at sea with them and they are beautiful(for a diesel). The balance is not quite perfect (but very close)as there is a phase difference between the cranks. I think the OP idea for a piston steam engine is very much worth some effort in design and development.</HTML>
Re: opposed piston engine
Posted by: Jim Crank (IP Logged)
Date: August 28, 2002 04:19PM
<HTML>Terry,
Sharp of you Sir. Yes, the inlet side crankshaft was indeed some degrees off from the exhaust side so they could supercharge it without blowing the air out the exhaust ports. 20° if I read my manual correctly. The exhaust piston closed first then the inlet.
Always wondered how F-M managed to collect the oil from the top crankshaft and not have it just fill the pistons and cylinders. I have sure seen them in operation and all apart; but never with just the top cover removed so I could see how they did this. My guess is some windage tray. Beautiful engine!
As a steam engine one would just have the two cranks exactly in phase, as then the original exhaust ports are all usable as steam exhaust ports. Good breathing, which the usual double acting unaflow does not have by any means. Also, having such area for the exhaust phase may possibly make it much smoother running with short cutoff and less need for super high vacuum.
I agree completely. If one just has to use a reciprocating engine, and not the Wankel as the alternative, then this configuration is one that really does adapt to a modern car with independent rear suspension. It does allow decent packaging in a chassis if you lay it down on it's side.
Use the Diesel's sleeves, pistons, cranks, rods. Sure makes it a lot easier to make a steam engine out of one and no compromises.
Think about a Corvette rear suspension with the engine down below the differential and the gearing going up, or at a 45° angle, from the cross shaft to the rear end, most compact.
Also easy to slip in a two speed transaxle with neutral idea with dog clutches. Having a neutal in my White was the car's finest feature.
Most certainly a very successful design and well worthy of adapting to steam. Definitely worth serious consideration.
I laid one out years ago just like that and ran into no problems at all in adapting all the 3-51 components. A powerful engine, on paper.
Jim</HTML>
Sharp of you Sir. Yes, the inlet side crankshaft was indeed some degrees off from the exhaust side so they could supercharge it without blowing the air out the exhaust ports. 20° if I read my manual correctly. The exhaust piston closed first then the inlet.
Always wondered how F-M managed to collect the oil from the top crankshaft and not have it just fill the pistons and cylinders. I have sure seen them in operation and all apart; but never with just the top cover removed so I could see how they did this. My guess is some windage tray. Beautiful engine!
As a steam engine one would just have the two cranks exactly in phase, as then the original exhaust ports are all usable as steam exhaust ports. Good breathing, which the usual double acting unaflow does not have by any means. Also, having such area for the exhaust phase may possibly make it much smoother running with short cutoff and less need for super high vacuum.
I agree completely. If one just has to use a reciprocating engine, and not the Wankel as the alternative, then this configuration is one that really does adapt to a modern car with independent rear suspension. It does allow decent packaging in a chassis if you lay it down on it's side.
Use the Diesel's sleeves, pistons, cranks, rods. Sure makes it a lot easier to make a steam engine out of one and no compromises.
Think about a Corvette rear suspension with the engine down below the differential and the gearing going up, or at a 45° angle, from the cross shaft to the rear end, most compact.
Also easy to slip in a two speed transaxle with neutral idea with dog clutches. Having a neutal in my White was the car's finest feature.
Most certainly a very successful design and well worthy of adapting to steam. Definitely worth serious consideration.
I laid one out years ago just like that and ran into no problems at all in adapting all the 3-51 components. A powerful engine, on paper.
Jim</HTML>
Re: opposed piston engine
Posted by: George Nutz (IP Logged)
Date: August 28, 2002 04:24PM
<HTML>Peter et al,
Peter I showed you the forgotten "Knowles" engine at my house that is a 16 cylinder double "wobble" plate engine with perfect balance. Knowles, in observing his engineering notes, was a superb stress analyst especially in that time period(1968-1972) as computers were not the rage, believe he was the chief stress analyst at Pratt and Whitney back then. Some of the best three dimensional work I have ever seen. He had studied several aircraft prototypes as cutting down the frontal area of the engine in a plane was paramount to high speed. Like many magnificient efforts his were dismissed.
It has a displacement of 138CID, 2% clearance volume and he rated it for 300HP/2000psi. As you have seen a most beautiful and rugged engine all up at 200#. Think 200HP practically possible. It is 20" long and 12" diameter with a center camshaft with five cutoffs that actuate 8 small poppet valves. All built on an old Bridgeport and South Bend lathe!! It has some thermodynamic weaknesses as far as heat loss problems but still a beautiful piece of work from one man pursueing his dreams. I had volunteered to let Jim use it in his high speed car if everything else fails--it has a few problems at this time to be worked out. Maybe I can send a few pictures to John Woodson of it---have been planning for several years to write a "Forgotten Knowles Engine" paper but time slips by. He contributed an oustanding piece of work that was rejected by Lear/SES/SPS/Dept of Transportation and like many lost everything in doing so. His work is an inspiration to me.
Best, George</HTML>
Peter I showed you the forgotten "Knowles" engine at my house that is a 16 cylinder double "wobble" plate engine with perfect balance. Knowles, in observing his engineering notes, was a superb stress analyst especially in that time period(1968-1972) as computers were not the rage, believe he was the chief stress analyst at Pratt and Whitney back then. Some of the best three dimensional work I have ever seen. He had studied several aircraft prototypes as cutting down the frontal area of the engine in a plane was paramount to high speed. Like many magnificient efforts his were dismissed.
It has a displacement of 138CID, 2% clearance volume and he rated it for 300HP/2000psi. As you have seen a most beautiful and rugged engine all up at 200#. Think 200HP practically possible. It is 20" long and 12" diameter with a center camshaft with five cutoffs that actuate 8 small poppet valves. All built on an old Bridgeport and South Bend lathe!! It has some thermodynamic weaknesses as far as heat loss problems but still a beautiful piece of work from one man pursueing his dreams. I had volunteered to let Jim use it in his high speed car if everything else fails--it has a few problems at this time to be worked out. Maybe I can send a few pictures to John Woodson of it---have been planning for several years to write a "Forgotten Knowles Engine" paper but time slips by. He contributed an oustanding piece of work that was rejected by Lear/SES/SPS/Dept of Transportation and like many lost everything in doing so. His work is an inspiration to me.
Best, George</HTML>
Re: opposed piston engine
Posted by: Peter Heid (IP Logged)
Date: August 28, 2002 08:33PM
<HTML>William,
The losses from the 2 connecting rods and the rocker arm are very small compaired to the efficiency gains with this design. The Rootes engine uses 4 rods and 2 rockers per cylinder. The Fairbanks Morse and Junkers engines are some of the most efficient compression ignition designed engines ever built. They are known for great reliability also.
Peter,
I will email you pictures of the crank, rods, rockers and such on the Rootes when I get a chance. Anyone else, just ask me at hihobmw@netheaven.com.
Peter Heid</HTML>
The losses from the 2 connecting rods and the rocker arm are very small compaired to the efficiency gains with this design. The Rootes engine uses 4 rods and 2 rockers per cylinder. The Fairbanks Morse and Junkers engines are some of the most efficient compression ignition designed engines ever built. They are known for great reliability also.
Peter,
I will email you pictures of the crank, rods, rockers and such on the Rootes when I get a chance. Anyone else, just ask me at hihobmw@netheaven.com.
Peter Heid</HTML>
Re: opposed piston engine
Posted by: G. B. Gilbert (IP Logged)
Date: August 29, 2002 05:27AM
Re: opposed piston engine
Posted by: Peter Brow (IP Logged)
Date: August 29, 2002 08:28AM
<HTML>GB, thanks for running the links to the OP engine pix. Intriguing designs. I especially liked the Rootes engine. Know any pix of the Fairbanks-Morse and Napier engines?
Peter, thanks for the offer. Looks like gearless linkages in opposed-piston engines have gotten more than just consideration.
Jim, crankcase water problem is easily solved in any of the designs that use rockers between cylinder and crank. The rocker can pivot a shaft with seals on it, keeping water away from the crank and mains. Other ends of pivoting shaft have arms to run the conrods and cranks. Then separation is needed for the oil/water in the chambers at the open cylinder ends. I'm none too clear on the mechanism of the Napier/Deltic; Ken Wallis didn't have any drawings handy when I visited him. From what little I know of the Deltic, a camshaft could be located where Wallis/Lear put the rotary valve, and poppet valve stems could radiate out to the cylinders at the 3 sides. With a bit of ingenuity, a tandem inlet valve system could be designed in for full-range cutoff control.
========
Odd that opposed piston engines came up here. I have recently been rebuilding the brake system on one of my old VW bugs (front wheels next, arg), and accumulating a pile of worn double-ended cast iron wheel cylinders. It occurred to me that with light reboring and homebuilt pistons (ductile iron billet?), these would make nice cylinders for small opposed-piston engines. Cheap, too; a complete new cylinder is $10. Perfect balance and free-breathing "double uniflow" layout could allow running at high rpms/expansion ratios for both good output and economy. Perhaps for running Lamont pumps and/or other auxiliaries? :)
Peter</HTML>
Peter, thanks for the offer. Looks like gearless linkages in opposed-piston engines have gotten more than just consideration.
Jim, crankcase water problem is easily solved in any of the designs that use rockers between cylinder and crank. The rocker can pivot a shaft with seals on it, keeping water away from the crank and mains. Other ends of pivoting shaft have arms to run the conrods and cranks. Then separation is needed for the oil/water in the chambers at the open cylinder ends. I'm none too clear on the mechanism of the Napier/Deltic; Ken Wallis didn't have any drawings handy when I visited him. From what little I know of the Deltic, a camshaft could be located where Wallis/Lear put the rotary valve, and poppet valve stems could radiate out to the cylinders at the 3 sides. With a bit of ingenuity, a tandem inlet valve system could be designed in for full-range cutoff control.
========
Odd that opposed piston engines came up here. I have recently been rebuilding the brake system on one of my old VW bugs (front wheels next, arg), and accumulating a pile of worn double-ended cast iron wheel cylinders. It occurred to me that with light reboring and homebuilt pistons (ductile iron billet?), these would make nice cylinders for small opposed-piston engines. Cheap, too; a complete new cylinder is $10. Perfect balance and free-breathing "double uniflow" layout could allow running at high rpms/expansion ratios for both good output and economy. Perhaps for running Lamont pumps and/or other auxiliaries? :)
Peter</HTML>
Re: opposed piston engine
Posted by: Jim Crank (IP Logged)
Date: August 29, 2002 02:14PM
<HTML>Peter,
The Napier Deltic and the Lear engine were the same.
Lear's was three crankshafts arranged in a triangle with two cylinders per side, so six cylinders and twelve pistons. Unaflow exhaust and one rotary inlet valve in the middle of it.
Wallace was a total fraud as you well know, not one original idea and let me tell you it was a real effort to have to sit there and listen to him B..S... Bill Lear with some of the most rediculous nonsense I ever heard. He was a master con artist. Although that first gas turbine car for Granatelli for Indy was a brilliant concept. Steam was another matter.
The Napier Deltic was the same arrangement and being British, insanely complicated. I think up to 32 cylinders in the biggest marine and sationary engines, although I could be mistaken on this, it might have been 24.
The Los Angeles Fire Department had a huge one in a trailer hooked to some gargantuan water pump. I heard it once at the harbor and went to investigate the strange sound. According to the Battalion Chief, when it worked it was a demon pumper; but was so labor intensive to maintain that they finally scrapped it.
I don't know where my F-M maintenance manual is right now; but it is the same design as the Junkers engine. If I find it and the sales literature I collected I'll Xerox it and send it to you.
I recall one thing of interest, the crankcase was a weldment.
Jim</HTML>
The Napier Deltic and the Lear engine were the same.
Lear's was three crankshafts arranged in a triangle with two cylinders per side, so six cylinders and twelve pistons. Unaflow exhaust and one rotary inlet valve in the middle of it.
Wallace was a total fraud as you well know, not one original idea and let me tell you it was a real effort to have to sit there and listen to him B..S... Bill Lear with some of the most rediculous nonsense I ever heard. He was a master con artist. Although that first gas turbine car for Granatelli for Indy was a brilliant concept. Steam was another matter.
The Napier Deltic was the same arrangement and being British, insanely complicated. I think up to 32 cylinders in the biggest marine and sationary engines, although I could be mistaken on this, it might have been 24.
The Los Angeles Fire Department had a huge one in a trailer hooked to some gargantuan water pump. I heard it once at the harbor and went to investigate the strange sound. According to the Battalion Chief, when it worked it was a demon pumper; but was so labor intensive to maintain that they finally scrapped it.
I don't know where my F-M maintenance manual is right now; but it is the same design as the Junkers engine. If I find it and the sales literature I collected I'll Xerox it and send it to you.
I recall one thing of interest, the crankcase was a weldment.
Jim</HTML>
Re: opposed piston engine
Posted by: Peter Heid (IP Logged)
Date: August 29, 2002 07:34PM
<HTML>Jim,
You said the sound drew you to see what they were running. The article says that the Rootes engines were hard to muffle and they barked quite a bit.
Peter Heid</HTML>
You said the sound drew you to see what they were running. The article says that the Rootes engines were hard to muffle and they barked quite a bit.
Peter Heid</HTML>
Re: opposed piston engine
Posted by: Mike Clark (IP Logged)
Date: August 29, 2002 08:31PM
<HTML>There is a sectional perspective drawing of the Napier Deltic at www.lexcie.zetnet.co.uk/delticengine together with some history. The eighteen cylinder 36 piston Deltic was used in pairs in the English Electric Co's very successful Deltic diesel electric locomotive for British Rail in the 1960's. It was a two stroke supercharged engine so had no valves or camshaft. One is displayed at the National Railway Museum in York - it is complicated but by all accounts was a very compact engine for the power developed. There were an awful lot of gears connecting everything together.
I remember very well the distinctive yowl made by the Rootes two stroke diesel which if I recall were always installed low down under the floor in buses and trucks - again due to compact size.
I only saw one Gobron-Brillié - about a 1908 four cylinder known to all in UK old car circles as Gobbling Billy. This has only one crankshaft and the pistons at the top of the cylinder are fixed to a crosshead with long connecting rods coming down to cranks which are at 180 degrees to those for the lower pistons. The advantage was "In an ordinary engine when an explosion takes place, there is a tendency to blow the cylinders off the crankchamber. In this engine there is no stress of this kind." Quite!! Pity Messrs Stanley didn't know about this.
Mike Clark</HTML>
I remember very well the distinctive yowl made by the Rootes two stroke diesel which if I recall were always installed low down under the floor in buses and trucks - again due to compact size.
I only saw one Gobron-Brillié - about a 1908 four cylinder known to all in UK old car circles as Gobbling Billy. This has only one crankshaft and the pistons at the top of the cylinder are fixed to a crosshead with long connecting rods coming down to cranks which are at 180 degrees to those for the lower pistons. The advantage was "In an ordinary engine when an explosion takes place, there is a tendency to blow the cylinders off the crankchamber. In this engine there is no stress of this kind." Quite!! Pity Messrs Stanley didn't know about this.
Mike Clark</HTML>
Re: opposed piston engine
Posted by: G. B. Gilbert (IP Logged)
Date: August 30, 2002 01:56AM
<HTML>more images
[www.fh-friedberg.de]
have a look at bild4
[www.fh-friedberg.de]
i liked it the instant i saw it ... so it must be impractical ..
[www.tpub.com]
[www.dself.demon.co.uk]
[www.iet.auc.dk];
[www.fh-friedberg.de]
have a look at bild4
[www.fh-friedberg.de]
i liked it the instant i saw it ... so it must be impractical ..
[www.tpub.com]
[www.dself.demon.co.uk]
[www.iet.auc.dk];
Re: opposed piston engine
Posted by: Brian Drake (IP Logged)
Date: August 30, 2002 06:34AM
<HTML>Okay, so it turns out that I was thinking of a free-piston engine, and not an opposed piston, still, here's the links in case anyone's interested:
[www.hut.fi]
[www.dynacam.com]
[boards.straightdope.com];
[www.hut.fi]
[www.dynacam.com]
[boards.straightdope.com];
Re: opposed piston engine
Posted by: Jim Crank (IP Logged)
Date: August 30, 2002 02:19PM
<HTML>Peter,
I was actually looking for it, after being told it was being tested at the harbor that day, heard this strange engine sound and figured that had to be the Napier, what with all the water cannons belching into the bay.
A rather high pitched yowl-moan-scream, very distinctive.
They said it took several days just to get into the engine if it needed repair.
Fire Departments then like their machinery on the simple side.
A seriously complex chain of helical gears linking the three crankshafts together. However, complexity or not, it was a very compact engine for the big displacement it had and put out loads of power.
Jim</HTML>
I was actually looking for it, after being told it was being tested at the harbor that day, heard this strange engine sound and figured that had to be the Napier, what with all the water cannons belching into the bay.
A rather high pitched yowl-moan-scream, very distinctive.
They said it took several days just to get into the engine if it needed repair.
Fire Departments then like their machinery on the simple side.
A seriously complex chain of helical gears linking the three crankshafts together. However, complexity or not, it was a very compact engine for the big displacement it had and put out loads of power.
Jim</HTML>
Re: opposed piston engine
Posted by: Dick Vennerbeck (IP Logged)
Date: August 30, 2002 09:21PM
<HTML>Jim and Peter,</HTML>
Re: opposed piston engine
Posted by: Dick Vennerbeck (IP Logged)
Date: August 30, 2002 09:41PM
<HTML>Jim and Peter, (Whoops don't hit the tab key!)
I recently saw a Napier engine like the one I think you are talking about. It was in a private collection just south of Santa Rosa. I did not realize what it was when I saw it. I understand they were made for PT boat use. I think the ID plate mentioned something like 3500 hp at 2100 RPM! It was super+turbocharged about 5 feet in diameter and looked more like an aircraft engine than a diesel. This engine met a hair raising demise. The engine had been set up on a test stand with cooling etc and no load. Upon startup it ran nicely with a very distinct sound. A few blips on the throttle and the engine ran away. The fuel was immediately shut off and the engine continued to scream. A piece of heavy plywood was forced over the flange of the 12" intake but the suction prevented the closing of the last few inches. By now everybody was panicking and the neighbors called the fire department about the unbelievable noise coming from next door. It was later determined that the engine was running on its own lube oil from a blown turbo seal. I will apparently never run again. The owner also has several other Big engines including an opposed Fairbanks diesel that he started for us. It also has a unique sound and was very smooth. The ground hardly trembled for that one. This gentleman has an open "Gas Up" day occasionally. John Woodson was the one who invited me and I'm sure he can give you all the details. It certainly was worth the visit.</HTML>
I recently saw a Napier engine like the one I think you are talking about. It was in a private collection just south of Santa Rosa. I did not realize what it was when I saw it. I understand they were made for PT boat use. I think the ID plate mentioned something like 3500 hp at 2100 RPM! It was super+turbocharged about 5 feet in diameter and looked more like an aircraft engine than a diesel. This engine met a hair raising demise. The engine had been set up on a test stand with cooling etc and no load. Upon startup it ran nicely with a very distinct sound. A few blips on the throttle and the engine ran away. The fuel was immediately shut off and the engine continued to scream. A piece of heavy plywood was forced over the flange of the 12" intake but the suction prevented the closing of the last few inches. By now everybody was panicking and the neighbors called the fire department about the unbelievable noise coming from next door. It was later determined that the engine was running on its own lube oil from a blown turbo seal. I will apparently never run again. The owner also has several other Big engines including an opposed Fairbanks diesel that he started for us. It also has a unique sound and was very smooth. The ground hardly trembled for that one. This gentleman has an open "Gas Up" day occasionally. John Woodson was the one who invited me and I'm sure he can give you all the details. It certainly was worth the visit.</HTML>
Re: opposed piston engine
Posted by: Jim Crank (IP Logged)
Date: August 31, 2002 12:43PM
<HTML>Dick,
That is for sure the Napier Deltic Diesel. PT boats in England used them.
Had the same thing happen on a boat with twin 6-71 Jimmy Diesels. Climbed on top of the valve cover and jammed life jackets into the air cleaner inlet.
Same thing, broken seal on the blower.
Jim</HTML>
That is for sure the Napier Deltic Diesel. PT boats in England used them.
Had the same thing happen on a boat with twin 6-71 Jimmy Diesels. Climbed on top of the valve cover and jammed life jackets into the air cleaner inlet.
Same thing, broken seal on the blower.
Jim</HTML>
Re: opposed piston engine
Posted by: Peter Heid (IP Logged)
Date: August 31, 2002 10:11PM
<HTML>Thank you all for the great information on this thread.
Brian,
A free piston engine can also be an opposed piston engine if it uses two pistons in the same cylinder. The definition I have found for free piston engines is that travel free in at least one direction. Many free piston engines worked on a ratcheting, rack and pinion. In some gas turbines the free, opposed piston engines are started in phase and after running for a moment they are put 180 degrees (if you imagine rotation) out of phase to smooth out the gas flow to the turbine. Very efficient pumps, too bad the turbines weren't so efficient.
Peter Heid</HTML>
Brian,
A free piston engine can also be an opposed piston engine if it uses two pistons in the same cylinder. The definition I have found for free piston engines is that travel free in at least one direction. Many free piston engines worked on a ratcheting, rack and pinion. In some gas turbines the free, opposed piston engines are started in phase and after running for a moment they are put 180 degrees (if you imagine rotation) out of phase to smooth out the gas flow to the turbine. Very efficient pumps, too bad the turbines weren't so efficient.
Peter Heid</HTML>
Re: opposed piston engine
Posted by: Peter Heid (IP Logged)
Date: August 31, 2002 10:16PM
<HTML>George,
When are you going to build a boiler that you can use to test run that creature ?</HTML>
When are you going to build a boiler that you can use to test run that creature ?</HTML>
Re: opposed piston engine
Posted by: Brian Drake (IP Logged)
Date: September 01, 2002 02:08AM
<HTML>Peter,
Someone should try hooking them up to a Tesla turbine, that might improve things. Here's a site on them:
[my.execpc.com];
Someone should try hooking them up to a Tesla turbine, that might improve things. Here's a site on them:
[my.execpc.com];
Re: opposed piston engine
Posted by: tom ward (IP Logged)
Date: September 01, 2002 11:10AM
<HTML>The tesla disc turbine has interesting properties as an expander, if the disc spacing is less than 1mm. Tesla built several himself and used them to generate electricity. Like all turbines it converts the flow of the fluid into torque whereas pistons convert pressure. The problem of steam consumption vs vehicle weight is the big trade off. Take your pick.</HTML>
Re: opposed piston engine
Posted by: Terry Williams (IP Logged)
Date: September 01, 2002 12:42PM
<HTML>Have you, or anyone you know (other than Jim Crank), actually built a Tesla turbine and tested it?</HTML>
Re: opposed piston engine
Posted by: David K. Nergaard (IP Logged)
Date: September 01, 2002 02:16PM
<HTML>I did a theoretical calculation and concluded a Newcomen engine would have higher efficiency! Also the Tesla wheel is inherently unsafe, very likly to explode long before it reaches efficient speeds.</HTML>
Re: opposed piston engine
Posted by: George Nutz (IP Logged)
Date: September 01, 2002 04:28PM
<HTML> I have done several thousands of calculations on the Tesla and it is very difficult to evaluate the spiral flow path and its viscious shear torque moment.
However the records of professional engineer Fritz Lowenstein, conducted at the big Edison station in NY way back then, showed results of (from memory) 37-42 pounds of steam per BHP-hr which was quite amazing at its time for using low pressure saturated/near saturated steam on two smaller Tesla turbines---about what a leaky Stanley engine would do on a bad day with low pressure saturated steam. They were certainly as efficient as very small conventional turbines. These tests were run at about 700FPS tip velocity and not the intended 1000FPS tip speed Tesla desired due to the limitations of available materials back then and that alone greatly reduced their efficiencies and increased their test steam rates. There is no record on any Tesly disc turbine ever exploding to my knowledge. These smaller units ran without any damage and were quite safe at these lower speeds, modern materials would greatly improve efficiency. As these are viscious shear devices highly superheated steam is not practical as it reduces the absolute viscosity of the entering steam greatly, as an auxilary or exhaust motor device could have great application. They can pass wet steam/condensed water without detriment which a standard turbine cannot. As a matter of fact DISCFLO pump has sold 100+ million dollars of water/sludge pumps using it backwards;Tesla had a patent on this use also. It is a shame that Tesla's desire to build a two stage compounded turbine was never built with two sets of discs on the same shaft, increasing the torque moment and efficiency. These tested Tesla turbines did not include his final patent ideas to further enhance disc stability. But then I have been a fan and member of TEBA for several years ---the present interests and development are in the gas turbine area as steam seems to be "old hat'. Please visit their website given by another poster. Several very technical papers have been written by PHD's in the last few years analyzing this device. Even 1 millimeter spacing is large as maintaining laminar(non-turbulent) flow is of importance to keep the drag/shear/torque forces conditions high. Unfortunately most recent hobby attempts have been done without any understanding or analysis of the device, such as stacking a bunch of table saw blades on a shaft and leaving the teeth on for better performance!!! Certainly has possibilities for an auxiliary motor using spent steam from a conventional steam engine and so easy to make.
Best, George</HTML>
However the records of professional engineer Fritz Lowenstein, conducted at the big Edison station in NY way back then, showed results of (from memory) 37-42 pounds of steam per BHP-hr which was quite amazing at its time for using low pressure saturated/near saturated steam on two smaller Tesla turbines---about what a leaky Stanley engine would do on a bad day with low pressure saturated steam. They were certainly as efficient as very small conventional turbines. These tests were run at about 700FPS tip velocity and not the intended 1000FPS tip speed Tesla desired due to the limitations of available materials back then and that alone greatly reduced their efficiencies and increased their test steam rates. There is no record on any Tesly disc turbine ever exploding to my knowledge. These smaller units ran without any damage and were quite safe at these lower speeds, modern materials would greatly improve efficiency. As these are viscious shear devices highly superheated steam is not practical as it reduces the absolute viscosity of the entering steam greatly, as an auxilary or exhaust motor device could have great application. They can pass wet steam/condensed water without detriment which a standard turbine cannot. As a matter of fact DISCFLO pump has sold 100+ million dollars of water/sludge pumps using it backwards;Tesla had a patent on this use also. It is a shame that Tesla's desire to build a two stage compounded turbine was never built with two sets of discs on the same shaft, increasing the torque moment and efficiency. These tested Tesla turbines did not include his final patent ideas to further enhance disc stability. But then I have been a fan and member of TEBA for several years ---the present interests and development are in the gas turbine area as steam seems to be "old hat'. Please visit their website given by another poster. Several very technical papers have been written by PHD's in the last few years analyzing this device. Even 1 millimeter spacing is large as maintaining laminar(non-turbulent) flow is of importance to keep the drag/shear/torque forces conditions high. Unfortunately most recent hobby attempts have been done without any understanding or analysis of the device, such as stacking a bunch of table saw blades on a shaft and leaving the teeth on for better performance!!! Certainly has possibilities for an auxiliary motor using spent steam from a conventional steam engine and so easy to make.
Best, George</HTML>
Re: opposed piston engine
Posted by: tom ward (IP Logged)
Date: September 02, 2002 10:02AM
<HTML>Read a patent not long ago of a drum turbine which claimed it could eliminate the need for a condensor since it tolerated saturated steam. To convert the latent heat into work the inventor incorporated the feed pump as a work load. A tesla turbine could do the same with a much simpler device.</HTML>
Re: opposed piston engine
Posted by: tom ward (IP Logged)
Date: September 02, 2002 10:26AM
<HTML>The patent number is 6,233,942. It is assingned to Thermaldyne LLC of Seattle.</HTML>
Re: opposed piston engine
Posted by: Terry Williams (IP Logged)
Date: September 02, 2002 11:29AM
<HTML>How do you suppose they seal the ends?</HTML>
Re: opposed piston engine
Posted by: Peter Heid (IP Logged)
Date: September 02, 2002 10:02PM
<HTML>What if you had a double acting, compound, opposed piston steam engine that used the space between the pistons for the first stage and the space below for the second stage expansion. I haven't tried drawing it or ciphering possable ratios and such yet, but you could maybe use an efficient unaflow and benefit from compounding also. The linkage and crankshaft(s) would be external of the steam area eliminating the troubles of oil/steam mixing and lubrication. The engine height could be kept low and though longer in the cylinders it would still be compact. Just a thought.
Peter Heid</HTML>
Peter Heid</HTML>
Re: opposed piston engine
Posted by: William L. Petitjean, P.E. (IP Logged)
Date: September 04, 2002 01:13AM
<HTML>I like the picture of the Comers engine -- very simple and direct. The best way to beat the water problem in the crankcase is to not beat it -- join it! My experience with Orkot bearing materials (originally developed in England for non lube rudder bearings) convinces me you could quite easily water lubricate the bottom end and fill the whole crankcase with exhaust steam. If you pumped water through the lubrication galleries into the Orkot bearings you would carry away heat buildup and create at least a very nice boundary lubrication scenario.
An automobile engine that requires no oil for lubrication would be a major improvement on existing practice. The steam engine can do it very nicely.
Bill Petitjean</HTML>
An automobile engine that requires no oil for lubrication would be a major improvement on existing practice. The steam engine can do it very nicely.
Bill Petitjean</HTML>
Re: opposed piston engine
Posted by: Terry Williams (IP Logged)
Date: September 04, 2002 02:26PM
<HTML>Bill, have you used Orcot bearings in an engine? I've just been looking up this material at: [www.sdplastics.com] and the 50,000 psi compressive strenth is quite impressive. Where do you get your orkot and how epensive is it?</HTML>
Re: opposed piston engine
Posted by: Terry Williams (IP Logged)
Date: September 04, 2002 02:26PM
<HTML>Bill, have you used Orcot bearings in an engine? I've just been looking up this material at: [www.sdplastics.com] and the 50,000 psi compressive strenth is quite impressive. Where do you get your orkot and how expensive is it?</HTML>
Re: opposed piston engine
Posted by: Graeme Vagg (IP Logged)
Date: October 06, 2002 01:52PM
<HTML>I saw an opposed piston steam engine demonstrated at a steam club meet in Sydney, Australia many years ago and it ran well and smoothly. It used a standard car engine crankshaft, con rods and pistons and had rocker arms on each side connecting the con rods on the crankshaft to the con rods on the pistons. There was no cylinder head - a pair of pistons came together in the horizontal cylinders at the top of the engine. The engine was as wide as a VW air cooled beetle engine but marginally higher.
At the time this development was shown, we were more excited about soluble oil in steam lubrication as used by Richard J Smith so possible lubrication benefits were not a consideration. The design had more lubrication pivot points anyway and we were concerned about the loads on the rocker arms. There were only about 10 of us there and no takers to do anything more with it. It was about 3 times the size of my V4 engines that had a similar displacement and it was not self-starting so not what we were looking for at that time. We were running engines on low quality shop boiler steam, on the lawn with no load or measuring equipment so could not assess steam economy. rpm potential or power output. The high expansion ratio was evident so good steam economy was expected. Perhaps we overlooked a new opportunity there but everyone had new ideas almost daily and not enough time and money to use them. When searching for higher steam economy and other benefits this type of engine should be tested at least to determine how good it is.
gv</HTML>
At the time this development was shown, we were more excited about soluble oil in steam lubrication as used by Richard J Smith so possible lubrication benefits were not a consideration. The design had more lubrication pivot points anyway and we were concerned about the loads on the rocker arms. There were only about 10 of us there and no takers to do anything more with it. It was about 3 times the size of my V4 engines that had a similar displacement and it was not self-starting so not what we were looking for at that time. We were running engines on low quality shop boiler steam, on the lawn with no load or measuring equipment so could not assess steam economy. rpm potential or power output. The high expansion ratio was evident so good steam economy was expected. Perhaps we overlooked a new opportunity there but everyone had new ideas almost daily and not enough time and money to use them. When searching for higher steam economy and other benefits this type of engine should be tested at least to determine how good it is.
gv</HTML>
Re: opposed piston engine
Posted by: G. B. Gilbert (IP Logged)
Date: October 08, 2002 02:58AM
<HTML>i think i've found an image of a model of the engine. try this:
[www.modelengineeringsoc.com];
[www.modelengineeringsoc.com];
Re: opposed piston engine
Posted by: john fehn (IP Logged)
Date: February 14, 2003 09:51PM
<HTML>~about water bearings: although my engineering books don't seem to mention water bearings at all, which would be ideal for steam engines, in 1972 or so i was interviewed for a job at 'Pacific Oxygen' co. close to oakland, calif. what I've never forgotten completely was an electrically driven pump which as i recall they said had been installed around 1910 or before, which had WATER BEARINGS. i thought is was a reciprocating type pump, but i wouldn't swear to it. the point is, water bearings already do exist and i wish i knew why they aren't used in steam engines. maybe they require energy intensive high pressure or something. don't know.
~~~~~~~~John Féhn~~~~~~~</HTML>
~~~~~~~~John Féhn~~~~~~~</HTML>
Re: opposed piston engine
Posted by: john fehn (IP Logged)
Date: February 14, 2003 10:57PM
<HTML>~~~opposed piston engine: forgive me if this has been thought of before, but it seems to me that the following might be an interesting way to build an opposed piston steam engine.
~~~suppose you have a vertical cylinder with occulting valves (such as typical uniflow exhaust valves) at both ends. lets suppose that both pistons are at the cylinder top, close together and the inlet ports are uncovered (open). the bottom piston now moves down under steam pressure until the cut off point is reached whereupon the top piston starts moving downward covering the inlet ports. both pistons are now moving downward but still moving apart (the expansion phase). the expansion phase ends when the bottom piston uncovers the exhaust ports and stops. the top piston continues downward exhausting the spent steam. both pistons now return to the top of the cylinder and the cycle repeats.
~~~advantages:
1) no complicated valves.
2) uniflow steam direction.
3) smooth starting due to no pesky compression phase typical of uniflow engines.
~~~disadvantages:
1) piston phasing mechanism not intuitively obvious.
~~~~~~~~John Féhn~~~~~~~</HTML>
~~~suppose you have a vertical cylinder with occulting valves (such as typical uniflow exhaust valves) at both ends. lets suppose that both pistons are at the cylinder top, close together and the inlet ports are uncovered (open). the bottom piston now moves down under steam pressure until the cut off point is reached whereupon the top piston starts moving downward covering the inlet ports. both pistons are now moving downward but still moving apart (the expansion phase). the expansion phase ends when the bottom piston uncovers the exhaust ports and stops. the top piston continues downward exhausting the spent steam. both pistons now return to the top of the cylinder and the cycle repeats.
~~~advantages:
1) no complicated valves.
2) uniflow steam direction.
3) smooth starting due to no pesky compression phase typical of uniflow engines.
~~~disadvantages:
1) piston phasing mechanism not intuitively obvious.
~~~~~~~~John Féhn~~~~~~~</HTML>
Re: opposed piston engine
Posted by: john fehn (IP Logged)
Date: February 16, 2003 04:20PM
<HTML>~Tesla turbine--yes terry. there is a gentleman named Scott Haines whom i have met at several steam auto club meetings in danville, ill. also at a mobile steam sosiety meeting in oak ridge, tenn. in 1999 where he tested his tesla turbine on the MSS computer controlled steam boiler. as i recall, he had done many empirical tests on various designs and this was his best to that date. again, as i recall, (i took no notes as teslas don't interest me much) the blades were about 9 inches in diameter spaced about one millimeter apart (don't remember how thick) and the blade stack was about two inches thick. i believe the gearbox was from a hand drill. i think it put out a little over two horse power. i have no idea how to contact him but maybe someone on the steam automobile club of america web site would know.
john Féhn
steamerjon@aol.com</HTML>
john Féhn
steamerjon@aol.com</HTML>
Re: opposed piston engine
Posted by: ANDRZEJ LACH (IP Logged)
Date: July 28, 2004 07:40PM
<HTML> During my service time i Polish Navy Im meet with opposite piston engine from submarine german boat its JUNKERS 2 stork diesel engine working on axial position for driven air high pressure compressor fited on end of connection rods the back way of pistons are realised by air pistons the compressor working on service pressure 400 bar rest data abowe this units Im forgoten</HTML>
Re: opposed piston engine
Posted by: ahKeong (IP Logged)
Date: August 04, 2004 04:09AM
<HTML>i am a undergraduate student, i would like to ask for ur help. where did i can get the detail information regarding the napier engine especially on the calculation on each phase angle.
thanks</HTML>
thanks</HTML>
Re: opposed piston engine
Posted by: ahKeong (IP Logged)
Date: August 04, 2004 04:09AM
<HTML>i am a undergraduate student, i would like to ask for ur help. where did i can get the detail information regarding the napier engine especially on the calculation on each phase angle.
thanks</HTML>
thanks</HTML>
Re: opposed piston engine
Posted by: hytham (IP Logged)
Date: August 06, 2004 07:03AM
<HTML>holla,Mr.....
please, I wanna some about<<opposet engine>>
his drawing &caractarests & all detals
thanks allot</HTML>
please, I wanna some about<<opposet engine>>
his drawing &caractarests & all detals
thanks allot</HTML>
Re: opposed piston engine
Posted by: Damijan Ruzic (IP Logged)
Date: August 12, 2004 03:34AM
<HTML>Well, it is the way, for sore, it is in the nature of the watter to be a lubricant. With some aditives it might work even better. It is an important benification compared to I.C. engine, wher watter can not be used as lubricant becouse of carbons and high heat converting it to steam in the most undesired way. However, gentlemen, I must sugest one more time that we all think about clean, cheap medium capable of fighting sone freeze. Without this solution, there is no steam engine built in modern car.
Damijan</HTML>
Damijan</HTML>
Re: opposed piston engine
Posted by: brian downes (IP Logged)
Date: November 16, 2004 07:38AM
<HTML>
the ts3 engine was very popular in australia in the 50's it was used for every type of operation that trucks can be expected to do i myself drove these trucks on interstate carrying both cars and general operations. on the sydney run we were towing 27 tons on a trip that consisted of 600 miles and took 17 hours,that will indicate that it was hard work all the way,i drove 3 of these,one did 600000 the car carrier did 700000 and the other one did 400000 on the adelaide run,none of these had any engine trouble which says a good deal for them i feel on the sydney run a petrol engine was giving 6 miles to the gallon the commer gave us 13 mpg which certainly was noted with great demand on the model.it got cold in the hills and when we put a heater in the truck it wouldn't work because the engine ran too cool,we covered the grille with newspaper and it still wouldn,t work the new trucks after that had a factory fitted metal plate behind the grille.i hope these figures are of interest to you and i would like to hear how they performed in other countries brian downes</HTML>
the ts3 engine was very popular in australia in the 50's it was used for every type of operation that trucks can be expected to do i myself drove these trucks on interstate carrying both cars and general operations. on the sydney run we were towing 27 tons on a trip that consisted of 600 miles and took 17 hours,that will indicate that it was hard work all the way,i drove 3 of these,one did 600000 the car carrier did 700000 and the other one did 400000 on the adelaide run,none of these had any engine trouble which says a good deal for them i feel on the sydney run a petrol engine was giving 6 miles to the gallon the commer gave us 13 mpg which certainly was noted with great demand on the model.it got cold in the hills and when we put a heater in the truck it wouldn't work because the engine ran too cool,we covered the grille with newspaper and it still wouldn,t work the new trucks after that had a factory fitted metal plate behind the grille.i hope these figures are of interest to you and i would like to hear how they performed in other countries brian downes</HTML>
Re: opposed piston engine
Posted by: Damijan Ruzic (IP Logged)
Date: March 13, 2005 09:14AM
<HTML>Halo,
The oposed piston steam engine could be a highly effective solution in case if U.S.S. principle is used, so if diameter of piston is much bigger than stroke. Another important item is air intake prior to hot watter or steam intake.
Let say so. You compress air betwen 2 broad pistons, than it is compressed and heated you inject hot watter and expand it. Than it is expanded you leave it out through exhaust valve in the bottom of cylinderand you inject fresh air through the valve in the top of cylinder, than you close these valves, exhaust valve first.. and you make a proces again...
Well, you can capture some waste heat later if you wish so and give it to the watter or combustion medium.</HTML>
The oposed piston steam engine could be a highly effective solution in case if U.S.S. principle is used, so if diameter of piston is much bigger than stroke. Another important item is air intake prior to hot watter or steam intake.
Let say so. You compress air betwen 2 broad pistons, than it is compressed and heated you inject hot watter and expand it. Than it is expanded you leave it out through exhaust valve in the bottom of cylinderand you inject fresh air through the valve in the top of cylinder, than you close these valves, exhaust valve first.. and you make a proces again...
Well, you can capture some waste heat later if you wish so and give it to the watter or combustion medium.</HTML>
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